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01 / INPUT
What should this flow prove?
Book a first session
New userReturning
Working validation build5 working days€600 fixed
Start the right appbefore you fund the whole one.
Turn one critical journey into a working Flutter build. Test it with real people, keep the source, then continue into a launch-ready MVP if the evidence is there.
Plan my validation build Get a written fit check before any call or payment.See the route to launch
PHASE / 01 WORKING VALIDATION BUILD
Validation phase€600fixed · source included
Test it now. Build the rest with evidence.
VALIDATE FIRSTLAUNCH NEXTYOU OWN THE CODEVALIDATE FIRSTLAUNCH NEXTYOU OWN THE CODE
01 / THE OFFERBuy the first proof.
Buy the first proof.
Not the whole risk.
One critical journey, a working build, and a clear decision about what deserves to be built next.
Inside the validation build
- One working core user journey
- Up to five focused screens
- Installable build, browser test, and source
- Existing API, lean backend, or test data
- One consolidated revision round
- A scoped route and quote to launch
€300 reserves the agreed slot. The remaining €300 is due only after you review the agreed flow.
50%after review
What you keep
deliverables = [
"android_build",
"browser_test",
"flutter_source"
]
What happens after proof
Production backend · accounts · payments · admin · app-store release · monitoring.
Those move into a separately scoped Launch MVP, starting from €3,200 additional.02 / THE PROCESSFrom assumption to
From assumption to
a real decision.
Five focused days produce something people can use—and a grounded route to launch.
Frame
Choose the product assumption and real user journey to test.
Shape
Lock the screens, data, users, and observable finish line.
Build
Turn the approved direction into a working Flutter build.
Test
Put the critical path in front of the people it is for.
Decide
Keep the source, stop, iterate, or continue into the launch MVP.
03 / EXPERIENCEReal product work.
Real product work.
Focused into five days.
The sprint is small by design. The experience behind it is not.
Flutter experience
3+years
building
building
Past the tutorial phase.
Hands-on Flutter and Dart work across multiple mobile and web products — shaped for real interfaces, real integrations, and clean handoff.
Production-minded from scope to source.
What that means in a sprint
01Responsive UIDesigned to hold together beyond one perfect screen.
02State that behavesClear loading, error, empty, and success states.
03Real integrationsREST, WebSocket, a lean backend, or controlled test data.
04Clean handoffA runnable build plus source you can keep.
04 / THE ROUTE TO LAUNCHValidate first.
Validate first.
Launch second.
The first build is not a throwaway mockup. It is a paid, working first phase that reduces uncertainty before a larger production commitment.
Phase 01 / Validation Build
5 working days · €600 fixedProve the core journey before funding the whole product.
You receive one working Flutter journey, an installable build, browser test, source, one revision, and a written recommendation for what should happen next.
AssumptionBuildUser testDecision
Phase 02 / Launch MVP
- 01
From €3,200 additional. Exact scope and price follow the validation build.
- 02
Add the production backend, accounts, integrations, analytics, and release work the product actually needs.
- 03
Ship a narrow first product to real users—not an undefined promise to build anything for one price.
Phase 01€600 fixed
DecisionStop or continue
Phase 02From €3,200+
OwnershipYour source
Plan phase one 05 / START HEREWhat must work
What must work
before you invest more?
Describe the product, its first users, and the one journey that matters. You will receive a direct fit / no-fit answer and the exact phase-one finish line before any payment.
01Describe the product and first testThe form prepares a complete email you can review before sending.
02Receive the validation planI confirm fit, screens, data, test users, finish line, and delivery date in writing.
03Approve and reserveOnly then does the first €300 reserve the slot. The final €300 waits until review.
06 / QUICK ANSWERSBefore you send
Before you send
the brief.
Is this a demo or the start of the real app?
It is a working validation build with source you keep. It is intentionally not production-ready, but it is designed to inform—and where technically sensible, become the starting point for—the Launch MVP.
Do I need finished designs?
No. Clear wireframes can work. The sprint simply does not include a full product-design phase.
Can you build the complete app afterwards?
Yes, when the validated scope is a fit. A narrow Launch MVP starts from €3,200 additional. The exact price, milestones, and release scope are quoted after phase one; complex products can cost more.
Can phase one include a backend?
Only the minimum needed to prove the agreed journey: an existing API, a lean test backend, or realistic test data. Production architecture belongs in the Launch MVP.
Will phase one be in the app stores?
No. You receive an installable Android build and browser test for validation. Store preparation and submission can be included in the Launch MVP.
What happens before payment?
I confirm the screens, flow, dependencies, and acceptance criteria in writing. If it does not fit, I say so.
What happens at delivery?
You review the Android build and browser test against the written acceptance criteria. Within-scope defects are fixed before the final €300 is due. The source is transferred after full payment.
Can I get a refund?
The €300 reservation is refundable until the agreed sprint begins. After work starts, it covers reserved capacity and work performed. If the agreed acceptance criteria are materially missed, I first fix them at no charge; if they still cannot be met, the €300 is refunded and the validation build and source may not be used.
Now reviewing new sprints
Start small.
Keep the route to launch.
Get a written phase-one scope before any call or payment. If the evidence supports the product, continue into a separately scoped Launch MVP.
Plan my first build07 / LEGALClear terms.
Clear terms.
No surprises.
Last updated 22 July 2026 · Business customers only.
Commercial terms
This page describes a productized B2B service and is not a binding offer. By sending a brief, the customer confirms that they act for a business or professional purpose. A contract exists only when both sides approve a written scope that expressly incorporates these terms and states the flow, screens, dependencies, dates, acceptance criteria, payment schedule, cancellation rules, and review window.
The phase-one Validation Build price is €600. The first €300 reserves the agreed slot and is fully refundable until the agreed start date or an earlier written instruction to begin. Once work starts, it pays for reserved capacity and work performed and is not refundable merely because priorities, preferences, or requirements change. If S5 cancels before delivery for reasons within its control, the first payment is refunded.
At delivery, the customer receives the agreed runnable Android build and browser test for review against the written acceptance criteria. Unless the scope states otherwise, the customer has three business days to accept the delivery or send one consolidated written list identifying any unmet criterion. If no such notice arrives in that window, the delivery is treated as accepted for invoicing.
One consolidated within-scope revision is included. Material within-scope defects are corrected at no charge before the final €300 becomes due. If an agreed criterion remains materially unmet after the stated remedy period, normally three working days, the first €300 is refunded and the customer must delete and may not use the validation build or source.
After acceptance, the final €300 is due within three business days. Custom source rights transfer only after full payment; third-party and open-source licenses remain unchanged. New features, changed requirements, additional flows, production hardening, and subjective preference changes are separate scope. Currency, applicable taxes, and transfer charges follow the written scope and invoice.
Phase one is a validation build, not a production, regulated, safety-critical, or app-store-ready product. Any Launch MVP is a separate engagement with its own written scope, price, milestones, warranty, and acceptance criteria. The indicative starting price shown on this page is not a binding quote. Czech law governs the agreement and Czech courts have jurisdiction unless the written scope says otherwise.
Privacy
The project form creates an email draft on your device. The website does not store its contents and nothing is transmitted to S5 until you send that email. Your email provider and the recipient's provider then process the message under their own terms.
The data controller is Jan Dobrohruška, IČO 22549838, Nerudova 327, 267 51 Zdice, Czech Republic; contact: hello@slicefive.com. Data may include your name, business email, company, project brief, links, correspondence, and—if a contract follows—billing and delivery records.
The data is used to assess fit, prepare the requested scope, communicate, prevent misuse, and perform or document an agreed contract. The legal bases are steps requested before entering a contract, contract performance, legal obligations, and legitimate interests in operating and protecting the business. Providing enquiry data is voluntary, but without the required contact and project details S5 cannot assess or answer the request.
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Unsuccessful enquiries are normally deleted within six months. Contract, invoice, and related records are kept for the applicable statutory periods, generally up to ten years where required. You may request access, correction, deletion, restriction, objection, or portability by email. You may also complain to the Czech Office for Personal Data Protection at uoou.gov.cz. No automated decision-making is used.
Provider information
Service brand: SliceFive (S5)
Provider and data controller: Jan Dobrohruška
Legal form: sole trader under Czech law
IČO: 22549838
Registered office: Nerudova 327, 267 51 Zdice, Czech Republic
Email: hello@slicefive.com
VAT status: not registered for Czech VAT
Registration: active in the Czech Trade Licensing Register since 3 February 2025
Governing law: Czech law